Sure, it can help accuracy. I usually pillar bed any of the cheaper synthetic stocks. Glass just won't cut it most of the time. Usually the forarm is not rigid enough. But if you glass bed a wood stock, and hog out the forarm, should be good enough. Pillar bedding only helps by solid contact to the stock but freefloating the barrel, if the same can be done with glass, it shouldn't make any difference in accuracy between the two.

Generally pillars are expensive to install. Sometimes running up to over 100 dollars where glass bed can usually be done much cheaper. And you can do it yourself.